Internal combustion engine



March 29, 1938. A. G. THOMAS 2,112,751

` INTERNAL COMBUSTION ENGINE Filed April 2l, 1936 5f Ey@ Ma/@3m PatentedMar. 29, 1938 UNITED STATES PATE NT OFFICE This invention relates tointernal combustion engines and especiallyto engines such as those.

used in motor cars and airplanes.

An object is to provide an engine in which preignition and knocking aregreatly reduced or eliminated, by the such as air to the cylinders.

Another object is to provide more complete combustion through theaddition of oxygen to the air supply, with the result that more power isgenerated, and less carbon monoxide.

Still another object is to provide novel and eiilcient mixing devicesfor fuel and air, also efiicient mixing systems Within the cylinders.

These and other objects will appear in th following description.

In the drawing:

Figure 1 represents a of an engine cylinder for increasing the oxygencontent of the air and for cooling the charge.

Figure 2` is a fragmentary, part-sectional elevation of a cylinder witha novel fuel-mixing and piston cooling design.

Figure 3 is an elevation of a multi-cylinder engine with a plurality ofair admission valves.

In Figure 1 piston I is reciprocated in cylinder 2 by connecting rod 3,in usual manner. Crank shaft 4 has fastened to it gear 5 which mesheswith larger gear 6 to which is fastened cam 1 so that both are rotatabletogether on shaft 8 which is fixed to some part of the engine. Smallgear 9, rotatable on shaft I0 fixed to the engine, is pivoted to pistonI2 by pivot 6I so that air is drawn in at I4 and forced through checkvalve I5 and intoheavy compression tank I6, when crank shaft 4 isvrotating. Other check valves, as indicated diagrammatically in cylinderI3, are provided as usual. The quantity of air supplied to tank I6willtherefore increase in direct proportion to the speed of the engine.

Pipe I1 leads from air tank I6 throughvcylinder head I8, so that airfrom this tank may be supplied to the cylinder 2, by opening throttlevalve I9. Throttle arm 20 is pivoted to rod 2l which is slidable in, and

part-sectional elevation framework. Compression spring 23, againstengine framework 24 and flange 25 on rod 2|, normally urges rod 2| in adownward direction to keep throttle valve I9 closed. Rod 2I is admissionof a cooling gas and associated mechanism respectively are shown.

28 to guardagainst excessive pressure in this tank. Check valve 60 maybeprovided.

Cooling unit 29; represented diagrammatically,

is placed contiguousto exhaust manifold 30 so by coil 33, it may also bereduced in temperature by radiating ns I 6b on cylinder I 6. and by astream of air. Air becomes heated upon being compressed and it isdesirable to cool it againgreatly reduced.

' 'I'he usual inlet and exhaust valves 34 and 35 Fuel inlet manifold 36is fastened to the cylinder block 31 as usual and is supplied with theair-fuel mixture by pipe 38 tegral with pipe 43, being supported byslotted or perforated wall 45, the perforations being shown at 45a.Cylinder face 46, perforated by holes 41, serves as bearing for one endof rotatable shaft 48, the other bearing being face 49 of pipe cylinder43. Face 49 is perforated by holes 50 to admit air. Motor 5I revolvesshaft 48 at a high rate of speed when it is energized by current fromthe car battery or from the generator. Fan 52 is fastened to andrevolves with shaft 48 and fastened tothe tips of fan 52 is cylindricalcentrifuge casing 53 to the inside of which are fastened axiallyparallel vanes which serve to impart a rapid rotary movement to the airas it is forced through pipe 43 by fan 52. Perforations 54 are providedin casing 53, and cylinder 44 has hole 55a leading to the atmospherethrough a suitable pipe.

Now if motor 5I is not revolving, air will be supplied to carburetor 39in a normal manner but when motor 5I is energized to revolve centrifuge53 at high speed the oxygen molecules beshown as being cooled t twogases will be considered.

, combustion chamber, on

The smaller the gap N separating centrifuge 53 and cylinder u the lessnitrogen will be mixed with the air drawn into the carburetor since,with small clearance. nearly all of the central air will pass out ofhole ll. Likewise the degree of separation of the oxygen can becontrolled by varying the speed of motor Il and by adjusting theclearance between centrifuge ll and pipe wall 43. Blades similar tovanes Il may be placed on the outside of centrifuge Il also.

Motor ll may have speed control lever ll so that the speed of the motor-may be increased as the speed lof the engine increases. l.

By increasing the oxygen density of the air mixed with the fuel morethorough combustion will take place with the result that more powerlwill be generated and less carbon and carbon monoxide will be formed.Oxygen may of course be supplied to the combustion chamber from a tankof compressed oxygen as tank Il which may be placed to f eed into tankli or through carburetor air pipe ll. In the past such feeding ofadditional oxygen would have been impracticable since it would havetended to lower the temperature necessary for pre-ignition but with myimproved fuel cooling system using injected air on compression strokes.it is possible to add oxygen.

The general principle governing the operation of this cooling system isthat of admitting to the the compression stroke, a certain amount ofcooled air under a pressure considerably higher than the maximumpressure developed in the combustion chamber during the f compressionstroke, before igniting the mixture with a spark. 'Ihis cooled air willthen rush into the fuel-air mixture in the chamber and will mixthoroughly with these vapors or gases and at the same time will expandand tend t cool since the pressure in the combustion chamber is lowerthan the pressure forcing the air in. Therefore, the added air` willexert a cooling effect on the fuelair mixture to offset the normalincrease of temperature of the stroke. The quantity of air admitted maybe increased as the compression is increased so that all during thecompression stroke there will be a balance between the cooling elect ofthe air and the heating effect of compression. the resulting temperatureof the fuel-air mixture may be kept below that necessary to causepreignition. but above the dew point of the fuel vapors. so thatcondensation will not take piace. Therefore, when the mixture is finallyignited by the spark the full effects of the charge will be realized andin addition there will be les trouble from knocking" which is oftencaused by too high a temperature within the cylinders. Furthermore, muchhigher compression ratios can be used than heretofore.

'I'he ai supply to the carburetor may be recontrol box 51 with` it maybe fed mixture on the compression.

In this way stricted by means of throttle Ilia so that the additionalcooling air will make up the normal air content for the mixture. or thecooling air may constitute an added quantity within reasonable limits.The reduced supply of air to the carburetor as a result of ,partiallyclosing throttle 40a will produce a choking eiiect so that more fuelwill be drawn into the cylinder. Then additional be forced into thecombustion chamber to form a normal fuel air mixture. but the quantityof both will be greater. This will b'e supercharging in effect and willproduce increased power.' Y g This system of cooling the fuel-airmixture directly is radically different from past methods which haverelied upon cooling various parts of the engine or cylinders to preventpre-ignition and knocking.v Such methods have never been verysatisfactory.

Engines built according to my system will, then have the followingadvantages: (l) higher compression ratio (2) greater power for 'a givenweight (3) less cooling troubles (4) less carbon monoxide and carbonformation (5) better acceleration, less pre-ignition and less knocking;(6) cheaper fuell may be used with satisfactory results.

Tank i6 is made with heavy walls to withstand fairly high pressures. If,for instance, the maximum pressure in chamber 21, on the compressionstroke is 150 pounds. a high pressure for former engines,- then tank i6would be made to withstand pressures of from 200 to 250 pounds persquare inch or more. These figures are merely illustrative, but givesome idea of the pressures involved.

Cam 1 is so shaped that it lifts rod 2l to open throttle valve I9gradually on the compression stroke, in proportion to the temperature ofthe compressed charge so that as more' heat is developed, more ai'r willbe admitted to cool the charge, so that a proper resultant temperaturewill be maintained. Cam 1 is shaped to cause a sharp cut-off of throttleil toward the end of the compression stroke, .lust before firing thecharge, but if desired the cut-off may be gradual and check valve Oilmay be provided to prevent the v expanding gases in chamber 21 fromrushing into tank Il, lwhen the charge is red. Throttle I9 could ofcourse be eliminated so that cooling air would be forced into thecylinder 2fat all times except on the firing stroke. This air wouldexert a beneficial cooling and scavenging effect on the exhaust strokebut would reduce the suction-on the intake.

Cam 1 as shown is fastened to gear 8 which reduces the rate of rotationof shaft I as compared to crank shaft be opened at the beginning of thecompression stroke and will be closed near the end of that stroke,remaining closed until the next compression stroke. But the speed ofrotation and shape of cam 1 may be so designed that air will be passedthrough throttle valve is in increasing amount during the compressionstroke; then valve *I9 may be cutoff during the firing stroke and may beopened wide during the exhaust stroke to cool the combustion walls andpiston. and atl the same time to help discharge the burned gases. Thencam 1 will open valve I9 the proper amount on the next compressionstroke.

Air may be admitted to combustion chamber f1 in any way desired or inany direction for best mixing or cooling effects. While tank il ispreferable, it is 4, So that throttle I9 will sis` chamber, cylinder vnot necessary since piston I2 may be made to force air directly intocombustion chamber 21, suitable timing being provided by a proper choiceof gearing and location of pivot 8|. Spark plug 82 is provided as usual.

haust manifold 88 rises. 'I'he temperature of the cooling air willtherefore be automatically regulated according to the needs of theengine. This would also be true in case tank I8 were cooled by a fandriven directly by some moving part of the engine. Likewise thermostatlcvalve I1a in line l1 will regulate the ow of air in proportion to thetemperature of the engine. Bimetal strip 11d is fastened to valve |1aand is linked at one end to valve arm I1e by means of pivoted arm i1! sothat valve 11a will be opened more asthe temperature of the enginebecomes hotter.

While only one cylinder is shown in Figure 1 it is obvious that the sameprinciple may be applied to an engine of any number of cylinders asshown in the fragmentary view of Figure3 in which air is suppliedthrough manifold 58a to the proper cylinders of engine E. control valvesA, B, C, and D. being cam operated as described in connection withFigure 1.

In Figure 2 cylinder 88 has cylinder head 64 with spark plug 85, asusual. Rotatable fan or mixer 66 is fastened to shaft 81 to which isfastened collar 68 which presses against the upper face of bearing 69 inwhich shaft 81 may be rotated at high speed by a motor or by beinggeared to some moving part of the engine. This rotating fan will thenmix the fuel and air,thor oughly on the intake and compression strokesand will also assist in forcing the burned gases out of exhaust port 10on the exhaust stroke. In'addition, fan 66 may be made of relativelythin metal of rather large area so that the metal `will take up heat onthe compression stroke to prevent preignition and will cool rapidly onthe exhaust stroke. This metal may be perforated if desired, to enhanceheat transfer and mixing.

Pump 1I draws fuel through pipe 12 from a suitable tank, not shown.'I'his pump may be of any suitable type and is preferably drivendirectly by the engine. It sprays fuel into heating tank 13 through pipe14, which may have a reduced orice. Tank 18 is heated by exhaust pipe 15so that the fuel in that tank is thoroughly vaporized before passinginto combustion chamber 16 through pipe 11 which is provided withthrottle valve 18. Air is forced into combustion chamber 18 by pump 19driven by the engine and through pipe 84 which is provided with throttlevalve 88. Cut-off valve 8l controls the ow of air through pipe 84 and asimilar cut-oil' valve 82 controls the iow of fuel vapor through pipe11. These two valves are linked together as shown so that they may beopened or closed simultaneously by rod cam 1 of Figure 1. Rod 83 and theassociated cam are arranged to open valves 8l and 82 at the beginning ofthe intake stroke of piston 85 and to close 4at the end of this stroke,to remain closed until the beginning of the next intake stroke.

Throttle valves 18 and 88, illustrated diagrammatically, may be linkedtogether by link 80a in similar manner to valves 8l and 82 so that theymay be manually opened or closed simultaneously to control the amount offuel vapor and air entering combustion chamber and cylinder 83 on theintake stroke whlleyalves 8i and 82 are open. If desired, anotherthrottle valve 88 may be placed in pipe line 12 to control the feedingof fuel to pump 1| and therefore to vaporizing chamber 13. Throttle 88,controlling the air supply, will naturally ,have a larger opening thanthrottle 18 controlling the fuel but they may be designed to i keep thesame fuel-air ratio for all throttle openings or by adjusting thelinkage points of the throttle arms similar to arms 81 and 88 on rod 88,the proportion of air to fuel may be increased or vice versa; as thethrottles are opened. It is obvious that valves 18 and 88 need not belinked together but could be separately controlled. Air flowing frompipe 84 strikes against fuel owing from pipe 11 creating turbulence thatwill assist in mixing the two. The air in pipe 84 may also be heatedbyxexhaust pipe 15.

Advantages of this type of mixing device'are that the fuel and air maybe definitely mixed in reaching the cylinder.

Piston 88 is provided with cooling fins 89 to reduce the temperature ofthe piston face and Walls. High voltage tube 90 charged by wire 8|connected to a suitable source of potential, may be fastened in cylinderhead 64 to irradiate the fuel-air mixture with X-rays, ultra-violetlight, or electrons Cil just before or at the time of ignition of themixture by spark plug 68. This is for the purpose of ionizing the fueland air molecules to promote better combustion. Pumps 1| and 18 may beeliminated and the air and fuel can be drawn into the cylinder by vacuumaction.

Many variations and combinations of the principles and devices outlinedin the foregoing Many other variations will be readily apparent to thoseskilled in the art.

What I claim is:

1. In an internal combustion engine, means for producing compression offuel mixture, meansfor pression is increased.

2. In an internal combustion engine, means for producing compression offuel mixture, means for ejecting burned gases, sparking means to ignitemeans for injecting cooling gas during the entire period of saidelecting burner gases. sparking. means to ignite said mixture. and meansfor compression, cooling gas into said mixture at higher pressure thanthe maximum compression pressure of said mixture.

'1. In an internal combustion engine, means for producing compression offuel mixture, means for electing burned gases, sparking means-to ignitesaid mixture, means for compressing air, means for cooling said air. avalve controlling the flow of said air into said mixture. said valvebeing automatically opened to admit said air to said mixture during saidcompression, and said valve being automatically closed to stop the i'iowof said air near the end of the periods of said compression.

8. In an internal combustion engine, producing compression of fuelmixture,

means for means for injecting. during said electing burnedgases.sparking means to ignite --\said mixture, means for compressing air, avalve controlling the ow of said air into said mixture, said valve beingautomatically opened to admit said air to said mixture during saidcompression, and said valve being automatically closed to stop the flowof said air near the end of the periods of said compression.

9. In an internal combustion engine. means for producing mixture of airand fuel. means for producing compression of said mixture, means forelecting burned gases, means for restricting the proportion of air insaid mixture. and means for admitting cooling air to said mixturelargely during the lattter part of said compression, in sufficientquantity to make normal proportions of air-to-fuel, and sparking meansto ignite the final charge of said air and said fuel.

10. In an internal combustion engine, means for producing compression offuel mixture, means for electing burned gases, sparking means to ignitesaid mixture, means for injecting cooling gas into said mixture duringsaid compression of said mixture. means for regulating the amount ofsaid gas injected so that the temperature of said mixture will bemaintained above the condensation' point and below the ignition pointuntil said mixture is ignited by said sparking means.

ALBERT G. THOMAS. v

